Effective-interaction approach to the many-boson problem

We show that the convergence behavior of the many-body numerical diagonalization scheme for strongly interacting bosons in a trap can be significantly improved by the Lee-Suzuki method adapted from nuclear physics: One can construct an effective interaction that acts in a space much smaller than the original Hilbert space. In particular for short-ranged forces and strong correlations, the method offers a good estimate of the energy and the excitation spectrum, at a computational cost several orders of magnitude smaller than that required by the standard method.

@article{77ce9c50-623a-4e4d-8a90-939a64609d11,
abstract = {We show that the convergence behavior of the many-body numerical diagonalization scheme for strongly interacting bosons in a trap can be significantly improved by the Lee-Suzuki method adapted from nuclear physics: One can construct an effective interaction that acts in a space much smaller than the original Hilbert space. In particular for short-ranged forces and strong correlations, the method offers a good estimate of the energy and the excitation spectrum, at a computational cost several orders of magnitude smaller than that required by the standard method.},
author = {Cremon, Jonas and Forssén, Christian and Åberg, Sven and Reimann, Stephanie},
issn = {1050-2947},
keyword = {boson systems,convergence of numerical methods},
language = {eng},
number = {1},
pages = {1--012707},
publisher = {American Physical Society (APS)},
series = {Physical Review A (Atomic, Molecular and Optical Physics)},
title = {Effective-interaction approach to the many-boson problem},
url = {http://dx.doi.org/10.1103/PhysRevA.79.012707},
volume = {79},
year = {2009},
}